xi ERYMANTHINE BOAR 279 Dicotylidae, contains but one genus? Uicotryles, with at most two species. The name of the animal is connected with the dorsal gland; the animal thus appeared to possess two navels. The Peccaries, exclusively confined to the New "World, differ from the Old-World Pigs in one or more important characters. They have only three toes on the hind-feet, and the stomach is com- plicated. Though the Peccaries have but small tusks they hunt in packs and are very dangerous animals to meet with. They owe, too, their safety from many foes to their sociable habits. Being nocturnal animals they are liable to the attacks of the Jaguar, which will speedily overpower and devour a Peccary that has strayed from, its herd, Fossil Swine.—The existing genera of the Pig tribe are alsc known in a fossil condition, Sus itself goes back as far as the Upper Miocene. jSits erymantfoius, the Erymanthine Boar, M known from beds of that age in Greece, England, and Germany, This genus is not known to have had a wider distribution in the past than it has in the present. Dicoiyles occurs in the Pleisto- cene of both 3^"orth and South America, the regions which i1 inhabits at the present day. The genus Listriodon, also Miocene is remarkable for having lophodont instead of bunodont teeth that is so far as concerns the molars, which resemble those o the Tapir. It was European and Indian in range. A numbei of genera, more remote from, the existing Pigs than those whicl have just been dealt with, are placed together in a speeia sub-family, Aehaenodontinae. The type genus, ^Achaenodon, hac a somewhat short skull for a Pig; and it is in general aspec and in the characters of the canine teeth highly suggestive o that of a Carnivore. The bunodont molars, however, are Suin€ as is the form of the lower jaw with a rounded angle. This i an Eocene animal found in Wyoming. JSlotJierivum * occurs chiefly in the Miocene of both iNortl America and Europe; but JK. uintense is Eocene. The orbit are completely encircled by bone in the more modern forms; thi is not the case in the last-described genus, with which J£ wintens agrees. The skull is also longer and more Pig-like. The a-ygo matic arch is powerful, with sometimes a large descending process such as is found in IMprotodon, more faintly in Kangaroos, and ii Sloths and certain extinct Edentates. The lower jaw has a pai 1 Marsh, ^timer. Jawm. Sci. slyii. 1894, p. 407.